code: def test_pretrained(self):
      kwargs = {
          "n_class": self.n_class,
          "pretrained_model": self.pretrained_model,
      }
  
      if self.pretrained_model == "cityscapes":
          valid = self.n_class in {None, 19}
      elif self.pretrained_model == "ade20k":
          valid = self.n_class in {None, 150}
      elif self.pretrained_model == "voc":
          valid = self.n_class in {None, 21}
  
      if valid:
          self.model(**kwargs)
      else:
          with self.assertRaises(ValueError):
              self.model(**kwargs)
  
file_path: chainercv/tests/links_tests/model_tests/deeplab_tests/test_deeplab_v3_plus.py
imports: import unittest
  import chainer
  from chainer import testing
  from chainer.testing import attr
  from chainercv.links import DeepLabV3plusXception65
  from chainercv.utils import assert_is_semantic_segmentation_link
  import numpy
label_desc: Use image node_id 1 for calling the TestDeepLabV3plusXception65Pretrained obj's underlying member method code with example usage: obj.test_pretrained() without return types